As a body heating device which can heat an inner area of the body intensively in order to treat cancer, a device is known (refer to Patent literature 1) whose magnetic-sensitive heat-generating material mainly includes fine particles of iron oxide restricting relative magnetic permeability to a high rank arranged in the body, and a magnetic flux that passes through the body is formed in the alternating magnetic field generator. As an example of an alternating magnetic field generator, there is a device that irradiates the magnetic flux of along-bodyheight direction, by driving the solenoid coil surrounding the body with an alternating current, and a device that generates a magnetic flux of across-body direction by a pair of magnetic poles which can be arranged at both sides of the body.
Also, in order to ease or prevent dielectrical heating of a surface layer of the body with the high-frequency electric field, a magnetic flux irradiator is known (refer to Patent literature 2) that has a cylinder of high dielectric material in the solenoid coil, the living body can be inserted easily therein. The magnetic flux irradiator is constituted so as to generate a magnetic flux of along-bodyheight direction by driving the solenoid coil with high-frequency current, then irradiate it to almost the whole body laid in the hollow part of the cylinder of high dielectric material. The shape of across-body direction cross section of the solenoid coil, i.e. the cross section of the solenoid radial direction (a cross section perpendicular to the solenoid axial direction), is plane circle.
In addition, there is a magnetic flux irradiator (refer to Patent literatures 3, 4) single-magnetic-pole-working type made so as to irradiate a magnetic flux of high density from one end (the working end) of the magnetic flux generating section to a limited area of the body. These magnetic flux irradiators are constituted of the small solenoid coil with a bar-segment-shaped magnetic core inserted for strengthening the magnetic flux and extending the reach thereof in the solenoid axial direction, and the solenoid coil generates the magnetic flux by high-frequency driving. Also, a device (refer to Patent literature 3) with a flux controlling coil outside the solenoid coil and a short section at the working end for further extending of the reach of the magnetic flux in the solenoid axial direction, and a device (refer to Patent literature 4) arranging the magnetic core thicker-diametered at the non-working end than at the working end, or forming a coolant flow path in the magnetic core for preventing overheat of the magnetic core, are known.    Patent literature 1: Japanese Patent Application Laid-Open No. 11-57031    Patent literature 2: Japanese Patent Application Laid-Open No. 2004-167031    Patent literature 3: Japanese Patent Application Laid-Open No. 2003-205040    Patent literature 4: Japanese Patent Application Laid-Open No. 2004-228289